JP2000129464A - Transparent substrate provided with thin-film stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transparent substrate particularly made of glass provided with a thin-film stack contg. at least one metallic layer arranged between two dielectric based coatings and having infrared reflecting characteristics and particularly low-emissivity. SOLUTION: Relating to a transparent substrate particularly made of glass provided with a thin-film stack contg. at least one metallic layer arranged between two dielectric based coatings and having infrared reflecting characteristics and particularly low-emissivity, and, in which the lower side has a coating contg. a wet layer 3 in direct contact with the metallic layer based on zinc oxide ZnO optionally doped with aluminum (ZnO:Al), and the two coatings based on dielectric material respectively have at least one layer having a high refractive index of >=2.2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a method, comprising: placing between two dielectric based coatings;
Infrared reflective properties, especially low-emissivity
Thin film stack containing at least one metal layer (thin
Particularly, the present invention relates to a transparent substrate made of glass and provided with a (film stack). The main application addressed by the present invention is the use of the substrate used for manufacturing thermal insulation windows and / or solar protection windows.

[0002] These substrates are necessary as the size of the glazed area of the rooms and passenger compartments continues to increase,
It is intended for installation in buildings and vehicles, with a particular aim to reduce the work of air conditioning and / or reduce excessive overheating. One type of known thin-film laminate that provides a transparent substrate with thermal properties, especially low-emissivity properties, suitable for the required application is a metal oxide type, in particular silver, disposed between two dielectric-based coatings. Of a metal layer. The stack is manufactured in a conventional manner using a series of deposition methods performed using a vacuum method, for example, a magnetic field assisted sputtering method where appropriate.

[0003] A layer having a protective role of preventing the silver from deteriorating can also be provided in the laminate. In this type of laminate, the silver layer largely determines the thermal performance, sun protection and / or low emissivity performance of the final window, while the dielectric layer is mainly obtained by interference Affects the optical appearance of the window. The dielectric layer also has the function of protecting the silver layer from chemical and / or mechanical attack.

[0004] The improvements made to windows with laminates of the type described above have, to date, increased the field of use of these windows, maintaining a satisfactory level of thermal and optical performance. However, with respect to the latter point, the thermal performance can make further improvements, especially those which result in a lower adiabatic coefficient k.

Accordingly, it is an object of the present invention to provide a substrate having a thin film stack of the above type, which has improved thermal performance but does not impair its optical performance. To that end, the present invention comprises at least one metal layer having infrared reflective properties and especially low emissivity, arranged between two dielectric-based coatings,
Underneath it was provided a thin-film laminate having a coating containing a wetting layer based on ZnO (ZnO: Al), optionally in contact with the metal layer, optionally doped with aluminum (especially made of glass). A) transparent substrates.

According to the invention, the two coatings based on said dielectric material each have at least one layer with a high refractive index, preferably 2.2 or more. In the present invention, high refractive index means strictly greater than 2. The combination according to the invention makes it possible to obtain a substrate having both a very low emissivity and a very high optical transmission, a characteristic of a performance not yet achieved in the prior art. .

In addition, the colorimetric appearance of the substrate of the present invention upon reflection is sufficient, and
l). In order to solve the problem by the present invention, the inventors first observed the following. That is, according to the prior art, it was first necessary to have a sufficiently thick metal layer to achieve a sufficiently low emissivity value.
It has been observed that the presence of zinc oxide ZnO as a wetting layer in direct contact with the metal layer makes it possible precisely to limit the thickness of said metal layer to the order of nm, generally of the order of 15 nm. Next, the inventors have confirmed that it is not easy to obtain a low value of the light reflectance _RL , despite the fact that the thickness of the silver layer is limited by the presence of zinc oxide ZnO.

The inventors have realized that a single high refractive index material must be inserted to take advantage of effects known per se. Surprisingly, the insertion of these types of materials on either side of the metal layer not only optimizes the desired anti-reflective effect, but also, according to the present invention, The inventors have discovered that the high refractive index layer does not come into direct contact with the environment, such as air, so that an excellent side color appearance upon reflection of the substrate can be obtained.

[0009] The functional metal layer is advantageously based on silver. Its thickness is 7 if it is desired to obtain windows with low emissivity and high light transmission (especially _TL of at least 70-80%), especially windows intended for mounting on buildings in cold countries.
It is selected from the range of ２０20 nm, especially 9-15 nm.
Rather, if a reflective window with sun protection intended for mounting on a building in a hot country is desired, the silver layer may be thicker, for example 20-25 nm (therefore obviously Light transmittance is very low, for example, 6
Less than 0% of windows will be produced).

[0010] In the laminate according to the present invention, it is preferable to provide a protective metal layer in contact with the layer having the infrared reflection characteristic immediately above the layer. The protection layer to be installed is niobium N
b, a single metal chosen from titanium Ti, chromium Cr or nickel or at least two alloys of these metals, in particular those based on an alloy of nickel and chromium (Ni / Cr), and a thickness of 2 nm It is as follows.
According to this variant, the metal or alloy constituting the protective layer may be doped with palladium Pd. The protective layer serves as a "sacrificial" layer for the purpose of protecting the functional layer when the next layer is deposited by reactive sputtering.

The wetting layer based on zinc oxide ZnO of the present invention has a thickness of 5 to 40 nm, particularly preferably 15 to 30 nm. With such a thickness, in addition to its wetting function, the wetting layer, in combination with a dielectric coating located above the functional layer, can contribute to adjusting the optical appearance of the laminate. Advantageously, the wetting layer is at least partially based on crystallized zinc oxide. Such a layer makes it possible to avoid being disadvantageous for the laminate from an optical point of view when the carrier substrate is subjected to a heat treatment such as thermal strengthening or bending.

Each of the high refractive index layers of the present invention, if present, may be located directly below the wetting layer, and may include niobium oxide Nb ₂ O ₅ , manganese-doped bismuth oxide Bi. Advantageously, it is based on a material selected from ₂ O ₃ : Mn, mixed oxide of zinc and titanium ZnTiOx, titanium oxide TiO ₂ , mixed oxide of tantalum and titanium TiTaOx, or mixed oxide of zirconium and titanium ZrTiOx. is there.

Of these materials, titanium oxide TiO ₂ is particularly preferred because of its compatibility with the other layers in the laminate of the present invention. According to a variant of the invention, the dielectric coating above the reflective metal layer comprises a set of superimposed layers, the set of layers having a refractive index of 2.2 or more, and a refractive index of at least 2.2. Low, particularly containing at least one layer of 1.8 or less, especially 1.6 or less. The layer is, for example, SiO ₂ , SiO
It can be a layer of N or SiOAl.

According to another variant of the invention, the dielectric coating above the reflective metal layer has, as another variant or in addition to the first variant, a set of superposed layers, One set of layers has on its top a layer having a refractive index of 2.2 or more, and has an intermediate refractive index, especially a refractive index of 1.9 to 2.1, on this layer, especially in direct contact with the layer. Layers. that is,
For example, a layer made of SnO ₂ , Si ₃ N ₄ , AlN, or ZnO may be used.

Obviously, these two variants are equally applicable to the dielectric coating under the reflective metal layer. To obtain a more achromatic substrate of the invention upon reflection, a dielectric-based coating placed above the metal layer is deposited with the following series of layers in the following order. a) a material having a refractive index ni _{-2 of} at most 2.2, in particular less than 2.2 or of 1.9 to 2.1 (for example S
1 or 2 of nO ₂ , Si ₃ N ₄ , AlN or ZnO)
Or more layers; b) 1 or below the last layer of n _i of at least 0.3 smaller especially 1.8 or material having less than 1.6 refractive index n _i-1 (e.g. SiO _2, SiON or SiOAl) 2 or more layers; c) the last one or more layers of material having a refractive index substantially equal n _i to the refractive index n _i-2 (particularly SnO _2, Si ₃
Layers produced by the N ₄ or AlN).

In this symbolic case, the reflective metal and the layers a),
TiO between the arrangements of b) and c) _TwoType refractive index
Advantageously, there is a layer having. Multilayer dielectric coating
Is advantageous. Especially because of the high refractive index and low
The difference in the refractive index between the layers where
Adjustments can be detrimental to optical properties
This is because excellent heat insulating properties can be obtained. This
These multilayer coatings allow windows to be
The appearance can be further improved.

In a preferred embodiment, one laminate meeting the criteria of the present invention is of the following type: Glass /
TiO ₂ or Nb ₂ O ₅ or ZnTiOx / ZnO
/ Ag / Ti or Nb / TiO ₂ or Nb ₂ O ₅ or ZnTiOx / SnO ₂ or Si ₃ N ₄ or (ZnO / Si ₃ N ₄ ) or (SnO ₂ / SnZnO)
x) the Si ₃ N ₄ was AlN or mixed Si-
It may be replaced with Al nitride.

The above substrate has a large emissivity ε of 0.0
Note that it is 25. The present invention also provides that the thin-film laminate has a low-emissivity or sunlight-protective multilayer glazing having the substrate on face 2 and / or face 3, where appropriate, face 5. glazi
ng), especially for double glazing.

Finally, the invention relates to a low-emissivity double glazing comprising at least one of the above-mentioned substrates and having a light transmission T _L of at least 72%.
The two-layer glazing with two glasses has a coefficient k of 1.4 w / when the two glasses are separated by a layer of air.
k · m ² or less, or is the coefficient k separated by a layer of argon is characterized not more than 1.1 W / k · m ^2.

Other details and advantageous features can be found in the following detailed description of the embodiments, which is described with reference to FIGS.
Will be clear. The present invention is not limited by these examples. Examples 1 and 2 are implemented according to the present invention. Examples 3 and 4 are provided as comparative examples.

In all of these examples, the deposition of the continuous thin film stack was performed using a magnetic field assisted sputtering method. Within the scope of the present invention, said depositing comprises:
Obviously, other methods can be used to control the thickness of the resulting layer appropriately. The following substrate on which the thin film stack was deposited was SAINT-GOBAIN V
A transparent silica-soda-lime glass substrate of the type marketed by ITRAGE under the name "PLANILUX".

It should be pointed out that the figures do not take into account various ratios between material thicknesses for clarity. Embodiment 1 (Embodiment according to the present invention) FIG. 1 shows that a titanium oxide T
There is a layer 2 based on iO ₂ , a wetting layer 3 based on zinc oxide ZnO, then a layer 4 of silver, a protective layer 5 of titanium Ti, and a layer 6 based on titanium oxide TiO _2, and on top of layer 6 It shows that there is a layer 7 of tin oxide SnO ₂ on the surface.

Accordingly, the laminate is a laminate of the following type. Glass _{/ TiO 2 / ZnO / Ag /} Ti / TiO 2 / S
nO ₂ Table 1 below shows the thickness in nm corresponding to each layer in the stack on the top surface of a 4 mm thick substrate.

[0024]

[Table 1]

The deposition conditions recommended for each layer to produce the above laminate were as follows. Layers 2 and 6 based on TiO ₂ were deposited under a pressure of 3 × 10 ⁻³ mbar in an Ar / O ₂ atmosphere using a titanium target. Z
The nO-based layer 3 was deposited under a pressure of 8 × 10 ⁻³ mbar in an argon / oxygen atmosphere using a zinc target.

The silver layer 4 was deposited under a pressure of 8 × 10 ⁻³ mbar in an argon atmosphere using a silver target. The Ti layer 5 was deposited under a pressure of 8 × 10 ⁻³ mbar in an argon atmosphere using a titanium target.
The layer 7 of SnO ₂ is coated with Ar under a pressure of 1.5 × 10 ⁻³ mbar.
Deposited in a / O ₂ atmosphere using a tin target.

The power and the moving speed of the substrate are the desired
The thickness was adjusted in a manner known per se to obtain the thickness. following
Table 2 shows the light transmittance values T, respectively._L(Percentage
T), the light reflectance value R_L(Also as a percentage), (L,
a^*, B^*A) Reflection in side color system ^*(R)
And b^*(R) value (no unit) and emissivity value ε (unit
No digits). These measurements are all D₆₅Lighting source
refer.

[0028]

[Table 2]

Next, the substrate 1 is assembled as a double-layer glass with another transparent bare glass substrate having a thickness of 4 mm via an intermediate argon layer having a thickness of 15 mm. Note that the thin film laminate is located on the surface 3. Table 3 below shows the same characteristic values T _L , R _L , a ^* (R), b ^* (R), and ε of the double-layer glass.
And shows the value of the coefficient ^{k (w / k · m 2} ).

[0030]

[Table 3]

Embodiment 2 (Embodiment of the Invention) In the thin film laminate shown in FIG. 2, a layer 7 based on tin oxide SnO ₂ , a layer 8 based on SiO ₂ having a refractive index of 1.45 and a nitride Last layer 9 in the laminate based on silicon Si ₃ N ₄
Except for coating with a thin film, the same as the thin film laminate of FIG. Therefore, the laminate has the following arrangement.

Glass / TiO_Two/ ZnO / Ag / Ti /
TiO_Two/ SnO_Two/ SiO_Two/ Si_ThreeN_Four SiO according to the invention_TwoLayer 8 based on is 15 nm thick
is there. SiO_TwoThe layer 8 based on
About 1.5 × 10 in atmosphere ^-3Plasma under mbar pressure
Utilized reactive sputtering method.

The layer 7 based on tin oxide SnO ₂ has a thickness of 25 nm. This layer was deposited in the same manner as layer (3) of Example 1. Layer 9 based on silicon nitride was 10 nm thick and was deposited under an atmosphere of argon / nitrogen under a pressure of about 8 × 10 ⁻³ mbar. The thickness of layer 6 based on TiO ₂ is 11 nm, and the remaining layers are the same thickness as the layers for Example 1.

Table 4 below shows T _L , R _L , a ^* (R), b of the monolithic substrate of this embodiment, respectively.
^* Indicates the value of (R), ε.

[0035]

[Table 4]

Next, this substrate is assembled with another transparent glass substrate having the same thickness of 4 mm through an intermediate argon layer having a thickness of 15 mm to produce a double-layer glass. The laminate of the present invention is located on the surface 3 of the double-layer glass. Table 5 below shows the same characteristic values T _L , R _L , and a of the double-layer glass.
^* (R), b ^* (R), ε, and the value of coefficient k (w / k
· M ² ).

[0037]

[Table 5]

Example 3 (Comparative Example) The thin film stack shown in FIG. 3 is identical to the thin film stack shown in Example 1 except that it has a single layer based on TiO _{2 according} to the invention. It is. This layer is included in the dielectric coating below the layer based on silver Ag.

Therefore, this laminate has the following arrangement. Glass / TiO ₂ / ZnO / Ag / Ti / SnO ₂ Table 6 below shows the T of the monolithic substrate for this example.
The values of _L , R _L , a ^* (R), b ^* (R), and ε are shown, respectively.

[0040]

[Table 6]

Next, this substrate is assembled with another transparent glass substrate having the same thickness of 4 mm via an argon intermediate layer having a thickness of 15 mm to produce a double-layer glass. The laminate of the present invention is located on the surface 3 of the double glass plate. Table 7 below shows
The same characteristic values T _L , R _L , a ^* (R),
b ^* (R), indicating the value of ε and ^{k (w / k · m 2} ).

[0042]

[Table 7]

Example 4 (Comparative Example) The thin film stack shown in FIG. 4 has the same structure as that of Example 1 except that it has a single layer based on TiO ₂ in a dielectric layer above a layer of silver Ag. It is the same as the thin film laminate. Therefore, the laminate has the following arrangement. Glass _{/ SnO 2 / ZnO / Ag /} Ti / TiO 2 / S
nO ₂ Table 8 below shows the T _L , R of the monolithic substrate of this embodiment.
The values of _L , a ^* (R), b ^* (R), and ε are shown, respectively.

[0044]

[Table 8]

Next, this substrate is assembled with another transparent glass plate having the same thickness of 4 mm via an argon intermediate layer having a thickness of 15 mm to produce a double-layer glass. The laminate of the present invention is located on the surface 3 of the double-layer glass. Table 9 below shows the same characteristic values T _L , R _L , a ^* (R), b of the double-layer glass.
^* Shows the (R), the values of ε and the coefficient ^{k (w / k · m 2} ).

[0046]

[Table 9]

[Procedure amendment]

[Submission date] January 5, 2000 (2000.1.5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Added

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a transparent substrate provided with a thin film laminate of Example 1.

FIG. 2 is a cross-sectional view of a transparent substrate provided with the thin film laminate of Example 2.

FIG. 3 is a cross-sectional view of a transparent substrate provided with a thin film laminate for comparative purposes in Example 3.

FIG. 4 is a cross-sectional view of a transparent substrate provided with a comparative thin film laminate of Example 4.

[Description of Signs] 1 ... Substrate 2 ... TiO ₂ layer 3 ... ZnO wetting layer 4 ... Ag layer 5 ... Ti protective layer 6 ... TiO ₂ layer 7 ... SnO ₂ layer 8 ... SiO ₂ layer 9 ... Si ₃ N ₄ layer

Claims (18)

[Claims] 1. The method according to claim 1, further comprising at least one metal layer having an infrared-reflective property and having a low emissivity disposed between the two dielectric-based coatings and directly under the metal layer. A transparent substrate, especially made of glass, provided with a thin film stack having a coating comprising a wetting layer based on zinc oxide ZnO (ZnO: Al), optionally doped with aluminum, two coatings based on a dielectric material Wherein each of the transparent substrates comprises at least one layer having a high refractive index of 2.2 or more. 2. The substrate according to claim 1, wherein the metal layer having infrared reflection properties is based on silver. 3. The thickness of the metal layer having an infrared reflection characteristic gives a low emissivity characteristic, so that it is 7 to 20 nm, especially 9 to 1 nm.
5 nm or 20 to provide sun protection properties
3. The substrate according to claim 1, wherein the substrate has a thickness of 25 nm. 4. The method according to claim 1, further comprising a protective metal layer disposed in contact with said layer having an infrared reflective property immediately above said layer. Board. 5. The protective metal layer is made of a single metal selected from niobium Nb, titanium Ti, chromium Cr or nickel Ni, or an alloy of at least two of these metals (particularly an alloy of nickel and chromium ( Ni / Cr)
5. The substrate according to claim 4, wherein the substrate has a thickness of 2 nm or less. 6. The thickness of the wetting layer is 5 to 40 nm,
6. The method according to claim 1, wherein the thickness is 15 to 30 nm.
The substrate according to any one of the above. 7. The substrate according to claim 1, wherein said wetting layer is based on at least partially crystallized zinc oxide. 8. The layers having a high refractive index include niobium oxide Nb ₂ O ₅ , manganese-doped bismuth oxide Bi ₂ O ₃ : Mn, and a mixed oxide of zinc and titanium ZnT.
IOx, titanium oxide TiO _2, mixed oxides of tantalum and titanium TaTiOx or be based on material selected from mixed oxides ZrTiOx zirconium and titanium to any one of claims 1 to 7, characterized in, The substrate as described. 9. A superimposed set of dielectric coatings above the reflective metal layer comprising a layer having a refractive index of 2.2 or more and a layer having a refractive index of 1.8 or less, especially less than 1.6. The substrate according to any one of claims 1 to 8, further comprising: 10. The layer having a refractive index of 1.8 or less is made of Si
O _2, substrate according to claim 9, characterized in that based on SiON or SiOAl. 11. The dielectric coating above the reflective metal layer contains a layer with a refractive index of 2.2 or higher, and a lower refractive index, especially 1.9 to 2. For example, SnO ₂ , Si ₃ N ₄ , AlN, Zn having a refractive index of 1
The substrate according to any one of claims 1 to 10, comprising a set of superimposed layers including layers such as O. 12. A series of the following layers in which a dielectric-based coating arranged above the metal layer is deposited in the following order: a) a refractive index n _i-2 of at most 2.2, in particular 2. a layer of one or more of less than 2 i.e. 1.9 to 2.1 material; b) the refractive index n _i-1 at least 0.3 less than the refractive index n _i of the last layer, in particular 1.8 1 or 2 of smaller material
Any one of the preceding claims, characterized in that c) the refractive index n _i has the last one or more layers of substantially equal material n _i-2; or more layers The substrate according to claim 1. 13. A TiO ₂ type layer having a refractive index of 2.2 or more comprises a reflective metal layer and said series of layers a), b) and c).
The substrate according to claim 12, wherein the substrate is disposed between the substrate and the substrate. 14. The laminate according to claim 1, wherein the laminate is:
TiO ₂ or Nb ₂ O ₅ or ZnTiOx / ZnO
Any one of the preceding claims, characterized in that the / Ag / Ti or Nb / TiO ₂ or Nb ₂ O ₅ or ZnTiOx / SnO ₂ or Si ₃ N ₄ or (ZnO / Si ₃ N ₄₎ The substrate according to claim 1. 15. The substrate according to claim 1, wherein the emissivity is at most 0.025. 16. Low-emissivity or solar radiation comprising a substrate according to claim 1, wherein the thin-film stack is present on surface 2 and / or surface 3 and, where appropriate, surface 5. Especially double glazing of multiple glazing plates for light protection. 17. A low emissivity double glazing comprising at least one substrate according to claim 1 and having a light transmittance T _L of at least 72%. 18. When the two glasses are separated by a layer of air, the coefficient k is 1.4 w / k. m ² or less, or double glazing according to claim 17 having two glass, wherein the coefficient k is 1.1 or less when the two glass are separated by a layer of argon.